This invention relates to new colloidal products containing calcium and/or magnesium, as well as sulfur and nitrogen, their preparation and their use particularly as additives in lubricating oils.
Overbasic detergent additives as a class have been known for a long time. Some of them and their preparation have been described, for example, in U.S. Pat. Nos. 2,865,956, 3, 150,088, 3,537,996, 3,830,739, 3,865,737, 3,953,519, 3,966,621, 4,148,740 and 4,505,830 and French Patent 2,101,813. Variants of the superbasification reaction exist which make use particularly of carbonates preformed from alkoxides and CO.sub.2 before contact with the alkaline or alkaline-earth salt of the acid compound; they are described particularly in U.S. Pat. Nos. 2,965,018, 3,932,289 and 4,104,180.
It is also known to modify overbasic detergent additives by incorporating boron derivatives, as described, for example, in U.S. Pat. Nos. 3,907,691, 3,929,650, 4,965,003 and 4,965,004.
The modification of overbasic detergent additives by certain carboxylic acids, boric acids or phosphoric acids has also been described in U.S. Pat. No. 4,328,111.
Further, French Patent FR-B-2,645,168 describes compounds containing thiophosphorus obtained by reaction of a sodium sulfonate or of a calcium sulfonate superbasified by sodium carbonate or calcium carbonate, with a phosphorus sulfide, in general P.sub.4 S.sub.10, this reaction optionally being followed by a reaction with a compound with active hydrogen, which could be water, methanol, isopropanol, a phenol, acetic acid, a dialkylphosphite, boric acid, phosphoric acid, ammonia, an amide, dimercaptothiadiazole or one of its derivatives. The compounds obtained, made soluble in a hydrocarbon medium by micellization, can be used as antiwear and extreme pressure additives in lubricating oils.
Finally, French Patent FR-B-2,681,872 describes and claims colloidal products containing boron and phosphorus, obtained by a process in which a borated overbasic alkaline or alkaline-earth sulfonate is prepared: A phosphorus sulfide is reacted with this product and the resulting product is separated. These products are also used as antiwear and extreme pressure additives in lubricating oils and greases. It is also possible to cite French Patent FR-B 2689031, which describes and claims colloidal products, themselves also usable as antiwear and extreme pressure additives in lubricating oils. They are defined as being obtained by reaction of a superbasified detergent compound (such as an alkali metal or alkaline-earth metal sulfonate, phenate, salicylate or naphthenate superbasified by an alkali metal or alkaline-earth metal carbonate or hydroxide) with a sulfur-containing carboxylic acid.